Nasser Navard Gol-Tapeh, an Iranian convert to Christianity, was arrested alongside the Azerbaijanis – Eldar Gurbanov, Yusif Farhadov and Bahram Nasibov – at a gathering of Christians in June 2016.

They were found guilty of “actions against [Iran’s] national security”, “missionary activities”, “organic relations with Sweden’s ‘Word of Life’ Church”, “soft subversive activities against the Islamic Republic regime” and “Zionist Christianity”.

The three Azerbaijanis were allowed to leave Iran in November 2016 and are unlikely to have to serve their sentences as they will not be forced to return.

But Nasser, a convert from a Muslim background, remains in Iran and will now have to serve his sentence after his appeal failed.

The Azerbaijanis, who are from Baku, were detained on 24 June 2016, along with several other Iranian citizens, while visiting Iran as guests of Iranian Christian groups. Most of the detainees were released after being interrogated.

He added: “We are deeply concerned by the continuing use of baseless charges that seem to act as smokescreen for religiously motivated charges and are utilised to suppress the right to freedom of religion or belief in Iran. So many Christians in Iran are accused of these baseless charges merely for attending prayer meetings in the privacy of their homes.”